I have one, along with a few others on his forum and I can tell you I'll never go back to the stock tune.
Don't get me wrong. If I never put the Diablo Performance tune in I'd be, and was Happy with the way the truck performed.
It's not like they don't go good to start with.
But with the Performance tune it is so much more enjoyable to drive.
The difference isn't noticable at first because it doesn't turn it into a dragster in comparison to the stock tune, but there is a difference.
Mostly noticable if you take out the Performance tune after using it a while and put the Stock tune back in. Then you notice a big difference.
It does help the milage but a Lot depends on how you drive.
I'm not always stabbing the pedal and I'd say I gained almost 2 miles per gallon on the average.
Again, depending on how I drive because it is fun to give it the gas once in a while with the Performance tune in it.
With the Performance tune I notice I'm hardly touching the gas pedal driving around town.
The big performance difference is when accelerating onto the highway or when passing someone on the highway.
As you push the pedal down it accelerates faster on it's own with out pushing the pedal further.
Also just cruising on the highway there is a noticable difference.
I find myself having to watch my speed a lot more because it not only goes faster but is smoother when it accelerates.
Also, just a note.
The performance tune requires 93 Octane.
A friend of mine put in the Performance tune but was running 87 Octane and it made his perform worse and Ping a real lot.
I run 93 anyway and in my opinion, it's worth it to run 93 with or without the Performance tune.
Anyway, I know I'm rambling but I personally Really Like the Diablo Sport programmer.
